NO.PZ2017092702000006
问题如下:
For a lump sum investment of ¥250,000 invested at a stated annual rate of 3% compounded daily, the number of months needed to grow the sum to ¥1,000,000 is closest to:
选项:
A. 555.
B. 563.
C. 576.
解释:
A is correct.
The effective annual rate (EAR) is calculated as follows:
EAR = (1 + Periodic interest rate)m – 1 EAR = (1 + 0.03/365)365 – 1 EAR= (1.03045) – 1 = 0.030453 ≈ 3.0453%.
Solving for N on a financial calculator results in (where FV is future value and PV is present value):
(1 + 0,030453)N = FVN/PV = (¥1,000,000/¥250,000)So,N = 46.21 years, which multiplied by 12 to convert to months results in 554.5, or ≈ 555 months.
看了答案后,我知道,题目中将年利率,换算成了按天计息的年度有效利率,然后算出年,再乘以12。 我把3%除以365。得出天利率0.0082%。(1+0.0082%)的30n次方等于4,把A和B代入等式后,得出3.9292和4.0312的结果。我就确定一下,此处比较应该和4比吧,是不是这么个比法,分别算两个值和4的差,前者约差0.0708,后者约差0.0312,后者小,所以选后者